Background associated with research of ambulatory surgical centers: Ambulatory Surgical Centers (ASCs) are facilities in which outpatient surgical procedures and a variety of medical interventions are performed. These centers are typically free standing, for profit, physician owned facilities. There are a number of reasons why procedures are performed in ASCs as compared to outpatient hospitals or doctors offices. These reasons include potentially lower overhead, lower co-payments, patient convenience and the ability to have dedicated specialized staff and protocols in order to provide more efficient services. As the majority of these ASCs are physician owned, there is growing concern that there are financial incentives to perform potentially unnecessary procedures at ASCs. The purpose of this research project is to analyze the use of ASCs for a variety of procedures within the Medicare population. In this research project, we will examine the use of ASCs over time to determine the growth in procedure rates and costs associated with these procedures performed at ASCs. We will also examine geographic and specialty variations in the use of these ASCs within the United States. This research will shed light on how ASCs are being used for procedures within the Medicare population. As Medicare is the single largest payor in the United States, this will provide valuable information on national trends in the use of ASCs. Study Design: The primary claims database that will be used in this study will be the U.S. Centers for Medicare and Medicaid (CMS) maintained Medicare Part B physician outpatient billing claims from 1996 through 2006. The Medicare Part A inpatient billing claims will also be used during the course of this research project. The Medicare Part B outpatient claims data will allow for a detailed analysis of services provided to a given patient over time. We will be abstracting all claims with an associated place of service code indicating that the procedure was performed at an Ambulatory Surgical Center. We will examine the trends over time in terms of what treatments are being performed at these ASCs. We will also explore the costs associated with these treatments and how these costs have changed over time. In addition, we will be analyzing the provider zip code to determine geographic variations in the use of ASCs. Women and minorities will be included as they are represented in the databases that will be used. Accomplishments: The extramural collaborator has obtained IRB approval for the study. Datasets have been obtained and preliminary analyses have been conducted. An abstract is being prepared for submission to the Association of Academic Physiatrists by the September 25, 2009 deadline. The design for the EMG research is presently in development.